I've just had a low ball offer accepted on a Black Star 4503 bench meter which shows a CAL error, so I'm expecting it to be a case of the battery being flat. I have the owners and also the service manual with the calibration procedure and it can be calibrated via the front push buttons in similar style to the HP3478A. This is yet another item for my growing collection of the TTi family of products as Black Star was I believe a brand name of theirs as the address is identical and the style very similar.
EDIT Ok I'll admit it, I just love all of those LEDs, one for each button, almost
Haha I saw that and thought about it for a couple of minutes
But wasnt convinced to slap an offer then eh. I felt sure that you would, so I went in a few £ higher than what I thought you'd go at Seriously I offered 50% of his asking price and considering there were a few watching, I was surprised to be accepted. I needed a new challenge in this lockdown to keep me from boredom
Attempting to be objective here, mostly unsuccessfully so decided I'd skip the potential hassle. Plus I was slightly worried that the battery had leaked on the board as well. Good job with the offer though. I reckon people are getting desperate to shift stuff. Best time to be a buyer
If the battery has leaked, it's currently not doing any real harm to the main circuitry as it seems to be functioning on its internal reference so any leakage should be treatable.
As long as you've not got the "tOtErr" you should be able to recover the cal data, as it stores 10 copies. You need to do it using the RS232 or GPIB, the service manual tells you how to see which of the 10 copies are bad, and how to replace them using the good copies.
Just out of curiosity, how much did you pay?
Oh, and also is it an early 20,999 count or later 40,999 count like mine? The service manual I have is only for the later version, it says you need a different manual for the early version.
EDIT: Some of the traces in the area of the battery are quite small; I had to do a bodge wire to fix the damage on mine. I recommend sorting the battery sooner rather than later!
Oh shit, I wasn't aware that were two variants of this meter
and I too have the manual for the 40,999 count one, so I need to back and search around for the correct one
The price, well the seller was listing it as BIN £39, so I offered £20 and got an acceptance within minutes.
I don't think I'm too bothered about being able to recover other copies of the CAL data, I should be able to reprogram the data via the push buttons and for the higher voltages where I don't have suitable references, I should be able to connect my HP3466A in parallel other higher supplies and get the 4503 to agree with the 3466A, which agrees with the other meters I have. What are the differences then between the 2 versions?